Use of
Gamma Knife technology for a meningioma

Meningiomas are usually benign tumors, i.e. tumors that grow slowly. They do not occur in the brain tissue, but in the membranes surrounding the brain. The name is taken from the anatomical description of these membranes, the meninges.

They account for around 15% of tumors in the skull and usually occur between 30 and 60 years of age. In some cases, there may also be multiple meningiomas.

Women tend to be affected more often than men. However, cell division is higher than normal (atypical) in rare cases, making the cells more aggressive locally. Metastases in other organs, such as with cancers practically never occur.

Diagnosis

A meningioma is diagnosed using MRI.

Meningiomas can occur anywhere in the meninges. A small meningioma does not cause any symptoms initially and is often discovered by chance. Tumors slowly get bigger if left untreated and compress the brain. This may cause an edema, with water accumulating in the nervous tissue. Headache, neurological changes, or epileptic seizures may follow. Since the various brain regions perform different functions, the type of symptoms will vary depending on the location of the meningioma.

At the skull base, the meninges also surround the cranial nerves. Therefore, meningiomas in the skull base often cause cranial nerve disorders. These include problems with smell and taste, abnormal facial sensations, double or impaired visual acuity.

Treatment of meningiomas depends on the size, location, and associated symptoms. Checkups are generally performed initially in the case of small “random findings” to estimate future growth behavior. However, large, symptomatic tumors, which trigger paralysis or epilepsy by compressing the surrounding tissue, normally require urgent surgery. If you cannot fully remove bones and meninges, meningiomas recur in almost 50% of cases (according to the literature 30–70%) despite “complete” removal. With partial removal, further growth can therefore be expected as standard.

Tumor location

The tumor location is therefore crucial. In the skull base, especially near large blood vessels or cranial nerves, these tumors cannot normally be fully removed without complications.

Radiosurgical treatment of small tumors

The Gamma Knife can successfully treat small meningiomas in the skull base which may still be asymptomatic. Growth is documented in successive MRI scans and successful treatment is possible even without prior surgery. In 90–95% of cases the further growth can be stopped permanently with a minimal risk of side effects.

Radiosurgical treatment of recurrent tumors or residual tumors

Recurrent or residual tumors can be treated effectively in a similar way using radiosurgery following conventional surgery without having to reopen the skull. We normally also manage to discernibly shrink the tumor tissue over a longer period. The chances of recovery are therefore excellent and life expectancy is unaffected.

Radiosurgery reduces risks

Treatment with the Gamma Knife eliminates the risks associated with a surgical procedure. Radiosurgical procedures do not cause vascular lesions, occlusions of major blood vessels in the skull, hemorrhaging, strokes, or infections.